Tuesday: Covered 01 slides (mathematical models) and 02 slides (building in software reliability).

Thursday: What does a requirements document look like? There are many topics that will span many lectures. 04-Requirements slides. The notion of atomic requirements. What makes a good atomic requirement? The difference between R-statements (in the optative mood) and E-statements about the environment (in the indicative mood). Mathematical models: contexts for the static part and machines for the dynamic par. A simple bank as an example.

Required reading: How to write requirements (see SVN)

Tuesday: Discuss Assignment 1. Complete Requirements/Mathematical Model.

Thursday: Discuss in detail the requirements document for the the return on investment calculator (this may take at least two weeks). This is in preparation for a large assignnment to be handed out next week. Slides on tabular expressions (due to David Parnas). Can check input for completeness and disjointness.

Required reading: A rational design process: How and why to fake it, Parnas and Clements here (available online via the library).

Discussion of Assignment 1 - right margin justification. Discussed ambiguities and incompleteness in the specification. R-descriptions versus E-descriptions.

ROI RD: Start at section 3, Dictionary. Mathematical Model for ROI.

Required Reading: Four Dark Corners of Requirements Engineering, Zave and Jacskon. See SVN

• Function tables (Parnas tables). Dell keyboard. Completeness, Disjointness and well-definedness.
• Unit testing tools for Java, C# and other languages. The V-diagram, Validation and Verification.
• Parnas on documentation and Jackson on Sofwtare Engineering.
• Structure of a requirements document. Context diagram. Atomic E and R-descriptions. Mathematical model. Links between atomic descriptions and Mathematical model. Acceptance tests. Tracability matrix. Developing acceptance tests from function tables as well as atomic descriptions.
• Requirements for safety critical systems. Fairness. Temporal logic. Modelchecking.